1. Field of the Invention
This invention relates generally to working platforms for performing work on structure, such as bridges. More particularly, this invention relates to such platforms which are erected below the decks of bridges.
2. Prior Art
There are many designs for working platforms which provide access to the underside of bridges or other structures. Examples of such designal may be found in the following U.S. patents:
______________________________________ U.S. Pat. No. Inventor Title ______________________________________ 3,066,757 Robinson Traveling Scaffold 3,076,552 Goodell Bridge Scaffold Apparatus 3,524,520 Tidwell Traveling Scaffold 3,550,723 Gentry Bridge Scaffold 3,708,038 Ewing, Jr. Cantilever Support 3,945,462 Griswold Hanger Brackets 4,044,858 Vikre Maintenance Device For Use Underneath Deck Structures 4,103,861 Buchler Arrangement for the Sectional Cantilever Projection of Multi- Panel Bridge Supporting Structures of Steel or Prestressed Concrete 4,271,927 Brown Inspection or Main- tenance Cradle 4,276,959 Barber Quick Way Scaffold ______________________________________
Heretofore, it has been believed that rigid trusswork or other such support was necessary to provide safe support. All of the above devices involve the use of relatively large structural members to support a platform under the deck of a structure. Erection and dismantling of such devices is expensive and time consuming. In many instances, special equipment, such as one or more cranes, is necessary for erection. Also, space restrictions will many times render some of these devices useless. Futhermore, many of the above devices are difficult to move from place to place on the structure and/or provide access to only a small area of the structure at a time. These devices also are not readily adaptable to various sizes of bridges or other structures.